Hi all, wanted to update on my experience with this download issue. I followed what a few have done, and closed and restarted, closed and restarted. I find what worked for me, is I logged in at playable, changed maps, did home instance, flew around etc etc. When I logged back out client would load a bit quicker each time. It finally FINALLY made 100%. However now when I load the client to play, I hit log in, and even though it has gone from 100% down to zero, the play button is there and I can play as normal. I feel the log in client is pretty broken at the moment.
But as I can log in and play I'm happy. Anet can deal with this and sort the issue. It's frustrating and unfair it's gone on this long. So people try to log in at playable, or close and start as others have suggested. If you see 100 completion, it might not say that again when you relaunch, but you should still be able to play. Weird, I can't explain it, but It's allowing me to play
Good luck everyone